This invention relates generally to the field of a tube with an internal layer comprising a polymer matrix and a captured compound, and more particularly to an apparatus for releasing a compound into an intravenous environment such as during intravenous drug administration.
Invasive drug administration can be a difficult procedure to alter, once it is initiated. The dynamic nature of drug administration can be difficult to anticipate. Feedback mechanisms can be used to monitor drug administration and exert control mechanisms on the system.
As drugs are becoming more sophisticated and endogenous compounds continue to be discovered and synthesized, mechanisms to deliver drugs in a more exact and versatile fashion will allow for fuller drug utility to be realized.
Drugs have been released at the tip of solid catheters by applying laser energy as an aid in tumor or local drug therapy. Compounds have been encapsulated with the anticipation of releasing them in a controlled way for many years in the form of timed release capsules, matrix embedded tablets, or controlled release granules. A catheter product exists whereby an interior coating of antibiotic provides prophylactic protection against infection by providing zero order release of drug from the interior surface.
Standard drug infusion consists of employing infusate of constant concentration with respect to an active compound. The volumetric flow rate determines the rate at which a drug or compound is delivered to the systemic circulation or organ system. Altering the rate of drug delivery necessitates altering the volumetric flow rate of the infusate apparatus. Various catheter designs and drug delivery systems are described in U.S. Pat. Nos. 5,304,121; 5,482,719; 6,086,558; 5,991,650; 5,795,581; 5,470,307, 5,830,539; 5,588,962; 5,947,977; 5,938,595; 5,788,678; 5,868,620; 5,843,789; 5,797,887; 5,773,308; 5,749,915; 5,767,288; and 5,665,077.
The present invention overcomes the shortcomings of previous designs and systems in a novel and unobvious way.
One aspect of the present invention relates to a method for providing a compound into a first flowing material. The method includes providing a section of tubing having an interior with a layer of a second matrix material bonded to the interior, releasably capturing a first compound in the second matrix material, and flowing the first material through the interior and over the second matrix material. Energy is applied to the second matrix material, and the first compound is released from the second matrix material into the first flowing material.
In another aspect, the present invention includes a flexible outer sheath with an interior surface and an exterior surface. A polymer matrix is attached to the interior surface of the sheath, the polymer matrix defining a lumen therethrough for flow of the liquid. A therapeutic agent is releasably captured by molecules of the polymer matrix.
Another aspect of the present invention includes a method for manufacturing a catheter. The method includes providing a sheath with an interior surface, and applying a layer of matrix material onto the interior surface. The matrix material is in a swelled condition. A rod is inserted into the interior of the flexible sheath. The flexible sheath is formed into a predetermined shape, and volume of the polymer matrix is shrunk. The rod is removed.
Another aspect of the present invention concerns a method for manufacturing an internally coated tube. The method includes providing a rod and a sheath with an interior surface and an exterior surface. The method further comprises applying a layer of a polymer matrix onto the surface of the rod, and placing the rod within the interior of the sheath. The method includes forming the sheath into a predetermined shape around the rod and removing the rod from the formed sheath.
Another aspect of the present invention concerns a method for providing a therapeutic agent to a biological unit. The method includes providing a compound releasably captured within a matrix material, the compound being releasable upon receiving an energy input. The method includes placing the matrix material and captured compound in fluid communication with a fluid which flows in a biological space of the biological unit. Energy is provided to the matrix material sufficient to release a portion of the compound, and the compound is released into the biological unit in an irregular pattern.
These and other aspects of the present invention will be apparent from the description of the preferred embodiment, the claims, and the drawings to follow.